NATIONAL WEATHER SUMMARY
AUGUST 2010
1st-7th…Scattered
storms moved into the Midwest on Monday, as a low pressure system pushed a warm
front into the region. Flow around the system pulled moisture in from the Gulf
of Mexico, and allowed for scattered showers and thunderstorms to stretch from
the Central and Northern Plains into the Midwest. Some of these storms turned
severe with strong winds and heavy rainfall. Many areas in the Dakotas saw
around an inch of rain, while parts of Michigan, Iowa, and Wisconsin also saw
rainfall totals near an inch. Early Monday morning, severe storms swept through
Norfolk, Nebraska and brought 3.22 inches of rain, 1.98 inches of that fell in 1
hour. Due to these slow moving and repetitive storms, floods remain a concern in
the Upper and Mid-Mississippi River Valley. Highs remained in the 80s across
most of the North-Central U.S. Some storms also developed in the Northeast as
the eastern edge of the front stretched into the region from the Midwest. This
brought overcast skies with light sprinkles, but northern New York state saw
some thunderstorms with quarter size hail reported in Beekmantown. However to
the South, hot and humid conditions persisted as high pressure dominated the
Gulf and Southeastern states. Heat advisories remain in effect as highs reached
well above 100 degrees, with high humidity this created heat indicies above 110
degrees. These conditions are favorable for afternoon storm development, thus,
scattered storms popped up over Georgia, Alabama, and the panhandle of Florida.
In the Southwest, high-level monsoonal moisture lingered over the four corners
and triggered scattered storms. Most areas saw less than a half of an inch, as
dry surface conditions allowed for rain to evaporate before it reached the
surface. Cortez, Colorado saw a mid-day total of 0.42 inches of rain.
Active
weather developed across portions of the Midwest on Wednesday as a nearly
stationary front reached across the Central Great Basin through the Central
Plains and into the Ohio Valley and the Upper Great Lakes. Clusters of showers
and thunderstorms developed near the boundary through the afternoon. Waves of
low pressure along the boundary supported chances of severe thunderstorms from
the Mid-Mississippi Valley through the Ohio Valley. Damaging winds gusts up to
66 mph were reported in northeastern Illinois, southeastern Michigan, Indiana,
and Ohio. Incidents of quarter to golf ball sized hail (1.00 to 1.75 inches in
diameter) were also reported in central Ohio. To the south, excessively hot
weather conditions persisted from the eastern Southern Plains through the
Eastern Valleys and across the Southeast as high pressure remained locked over
the deep South. Heat Advisories and Excessive Heat Warnings remained over these
regions as scorching daytime temperatures pushed past the century mark and heat
index values reached well into the 120s. Along with these baking hot conditions,
areas of scattered showers, locally heavy rainfall, and thunderstorms developed
across the Southeast. In the West, a low pressure trough triggered scattered
showers and thunderstorms throughout portions of the Central Great Basin as it
trekked northeastward from northern Utah toward Wyoming.
Scattered storms persisted in the Southeast on Friday, while mild and pleasant
weather returned to the Great Lakes. As high pressure built over the Eastern
half of the country, a stationary front pushed into the Southeast, and stretched
from the Mid-Atlantic states and into the Southeast and Southern Plains. This
front pulled in ample moisture from the Gulf of Mexico and allowed for
thunderstorms to develop. Some of these storms turned severe with strong winds,
and heavy downpours. Wind gusts at 64 mph were reported in Seaside, North
Carolina, while 1.76 inches fell in Whiteville, North Caroline. Most areas along
the front saw between a half and an inch of rain. This gave little relief from
the extremely hot and humid conditions that the region has experienced over the
week. However, heat indicies still reached above 100 degrees in some areas. To
the north, higher pressure allowed for a few patchy clouds and mild temperatures
in the 80s over the Midwest and Great Lakes regions. In the west, mild storms
popped up across the Southwest as monsoon moisture lingered over the Four
Corners. The Northern Rockies also saw some scattered showers due to a trough of
low pressure to the west pushing mild moisture in from the Pacific Ocean. The
rest of the West Coast remained sunny and warm with some low clouds lingering
along the coasts.
8th-14th…Cloudy
skies covered the much of the north-central Gulf of Mexico on Wednesday as the
very broad and elongated Tropical Depression Five became centered at about 150
nautical miles southeast of the mouth of the Mississippi River. The depression
continued to move northwestward toward southeastern Louisiana with maximum
sustained winds of 25 knots and gusts to 35 knots. Bands of showers and
thunderstorms developed around the periphery of the depression but remained
limited in the center. Outer rain bands affected the eastern and north-central
Gulf through the afternoon. Meanwhile, to the north, a frontal boundary reached
across the Ohio Valley and the northern Mid-Atlantic with showers, thunderstorms
and strong winds. The boundary also separated the hot and humid air of the South
from the relatively cooler Canadian airmass in the north. Oppressive heat
continued to plague the central and southern states of the nation with daytime
highs reaching past the century mark and heat indices soaring into the lower
120s. Poteau, Oklahoma experienced the worst of these conditions with a
dangerously high heat index of 121 degrees. These baking hot conditions kept the
region under numerous Heat Advisories and Excessive Heat Warnings through the
afternoon. In the West, a fairly strong boundary moved from the Pacific
Northwest into parts of the Intermountain West and the Northern High Plains with
chances of showers and thunderstorms. Meanwhile, monsoon moisture sparked
isolated showers and thunderstorms in the Southwest, while low clouds and fog
lined areas of the West Coast.
Scattered storms swept through the Northern Plains and Upper Midwest on Friday,
while rain persisted in the Southeast. A low pressure system skirted along the
Canadian border which created a cold front that stretched southward into the
Northern US. The system has kicked up scattered showers and thunderstorms, some
of which turned severe with heavy rain and strong winds. Heaviest rainfall hit
Minnesota with 2.76 inches reported in Glencoe, while Minneapolis saw 2.59
inches of rain. Strong winds blew down multiple trees in Tomah and Wilton,
Wisconsin, with gusts up to 69 mph. To the south, the remnants of Tropical
Depression Five lingered over the northern Gulf of Mexico and continued pushing
ample moisture onshore over the Gulf states. This allowed for rain and
thunderstorms to persist from Louisiana to the panhandle of Florida. Storm
totals since Wednesday range between 3-5 inches. On Friday, Hammond, Louisiana
saw a mid-day total of 2.05 inches. Elsewhere in the East, a ridge of high
pressure built over the Mississippi River Valley and extended to the East Coast.
This allowed for another day of sunny skies and hot temperatures. Heat
Advisories remained in effect as highs remained near 100 with near 100%
humidity, thus heat indicies reached well above 110 degrees. Meanwhile, the West
Coast saw the beginning of a warming trend as a trough of low pressure moved off
to the east and a ridge of high pressure built in from the west. Morning coastal
clouds quickly pushed offshore and allowed for plenty of sunshine to stretch
from the Pacific Northwest to southern California.
15th-21st…A
front stalled over the Eastern U.S. on Monday, while another system moved into
the Central Plains. A ridge of high pressure built over the Eastern U.S. and
shoved a cold front into the Southeast. The system stretched from the Northeast,
down New England and the Mid-Atlantic States, and into the Tennessee and Lower
Mississippi River Valleys. In addition, the remnants of Tropical Storm Five
hovered over the northern Gulf of Mexico and continued pushing ample moisture
onshore. Thus, extremely warm and humid air was trapped over the Southeast and
Gulf states, which allowed for scattered showers and thunderstorms to develop.
Highs remained in the 90s across the region with heat index of 118 degrees in
Farmville, Virginia. To the North, the front kicked up some severe storms with
hail reported in Canaan Center, New York and multiple trees and power lines
reported down across the state of New York. Meanwhile in the Central U.S.,
another system strengthened as it moved off the Rockies and into the Plains. The
system kicked up scattered showers over the Four Corners as well as the Central
Rockies, while it also pushed a front into the Plains. In Silver City, New
Mexico, 0.94 inches of rain was reported, while wind gusts associated with a
thunderstorm reached up to 70 mph in Stuart, Nebraska. Parts of northern Texas
saw periods of heavy rain and strong storms, with rainfall totals ranging
between a half inch to an one inch of rain. These storms brought flooding
concerns to the Southwest and Central Plains. The rest of the West Coast saw hot
and dry weather as a ridge of high pressure built over the region. Heat and fire
warnings have been issued due to dry and windy surface conditions that allow for
rapid fire spread.
A
frontal boundary associated with a low pressure system centered over Hudson Bay,
Canada became stalled across the northern tier of the Midwest. The disturbance
sparked areas of scattered showers and thunderstorms in the Dakotas, northern
Minnesota, northern Wisconsin, and the western portions of the Michigan Upper
Peninsula. Increased instability along the front lead to chances of severe
weather activity with hail and possible tornadoes from the Northern Plains
through the Upper Great Lakes. Thus far, quarter sized hail (1.00 inch in
diameter) was reported in Wilkin County, Minnesota. Temperatures across the
region remained comfortably warm through the afternoon with highs in 70s to 80s.
Meanwhile, more active weather developed in the southeastern quadrant of the
nation as another frontal boundary extended from the Mid-Atlantic through the
Southern Plains. Ample moisture from the Gulf of Mexico heightened instability
along the front and aided in producing scattered showers, locally heavy
rainfall, and thunderstorms through the afternoon. Prolonged periods of rainfall
created chances of flooding and flash flooding from southeastern Louisiana
northeastward through the western areas of Virginia and North Carolina. Hot and
humid conditions remained over areas from the Southern Plains through the
Southeast and the southern Mid-Atlantic with temperatures in the 90s and lower
100s. Hilton Head Island, South Carolina experienced the worst of these
conditions with a heat index of 121 degrees. Calmer and drier weather conditions
developed throughout much of the West.
A warm
swept through the Midwest, which kicked up severe weather on Friday. The system
developed from a low pressure system that moved off the Rockies and into the
Northern Plains and Upper Midwest. Flow around the system pulled in warm and
moist air from the South, which created a front that triggered showers and
thunderstorms over Minnesota, Iowa, and Illinois. Most areas saw 1-2 inches of
rain, while hail was reported in Mercer and Kennan, Wisconsin. Strong winds
developed south of this system, with signs blown down in St. Clair, Missouri and
wind gusts up to 70 mph in Smithville, Missouri. Northern Minnesota saw the
heaviest rainfall with 2.13 inches reported in Bemidji. Behind this front saw
more mild temperatures with highs in the 70s across the Northern Plains, but the
Southern Plains saw highs near 100 with heat indices well into the 100s. Poteau,
Oklahoma saw a heat index up to 117 degrees. Thus, uncomfortably humid
conditions persisted across the Southern Plains.
Meanwhile, in the East, a ridge of high pressure dominated the North, while a
front lingered over the Southeast. The front continued to kick up scattered
showers, none of which have turned severe, with rainfall totals ranging from 0.5
to 0.75 inches. New England and the Northeast saw mostly sunny skies and
pleasant conditions with highs in the 80s.
Out
West also saw some mild weather on Friday. A trough of low pressure pushed a few
low clouds onshore, allowing for a cool and cloudy day along the coast. However,
inland areas remained hot and sunny.
22nd-28th…Areas
near the East Coast continued to experience wet and gloomy weather on Wednesday
as a low pressure trough passed through the eastern third of the nation. In the
Northeast, wrap-around flow associated with an offshore low pressure system that
passed east of Cape Cod, fueled isolated to scattered rain showers across
eastern New York and much of New England. Meanwhile, an associated frontal
boundary located off the East Coast produced additional scattered showers over
portions of the Mid-Atlantic and the Central Appalachians. To the south, the
tail of the aforementioned front supported scattered showers and thunderstorms
from the Carolinas through Florida as the disturbance stalled over southern
Georgia, the Florida Panhandle, and the northern Gulf of Mexico by the
afternoon. Numerous thunderstorms and persistent rains over the western Florida
Peninsula translated into chances of minor flooding and coastal flooding. Behind
the active weather near the East Coast, a cold front triggered morning showers
over portions of the Upper Great Lakes before it became positioned from the
Lower Great Lakes through the Tennessee Valley by the afternoon. In the Central
U.S., high pressure brought fair skies and pleasant temperatures to much of the
Plains. To the east of this high, areas from the Great Lakes through western
Texas experienced below average temperatures. In the West, dry and hot
conditions continue over much of the region as a strong ridge of high pressure
located over the region edged eastward. Portions of the Northwest, parts of the
Sierras, and parts of the southwestern deserts remained under Red Flag Warnings
due to possible fire weather activity. Elsewhere, monsoon moisture triggered
showers over eastern Arizona and portions of New Mexico and Colorado.
Scattered showers and thunderstorms persisted across the Southeast, as a front
lingered on Friday. A stationary front extended off the coast of the
Mid-Atlantic states and stretched into the northern Gulf of Mexico. This system
has hovered over the region for the past few days, thus, flooding problems
threatened many areas. Rainfall totals along the front ranged from a half of an
inch to nearly 2 inches. Biloxi, Mississippi saw 2.26 inches of rain associated,
while Pensacola, Florida saw 1.68 inches of rain. These storms have not yet
turned severe because large hail and strong winds have not been reported. Most
areas along this front remained hot and humid with highs in the 90s and heat
indicies well over 100 degrees. Elsewhere across the Eastern half of the
country, a ridge of high pressure extended from the Plains, over the Mississippi
River Valley, and into New England and the Northeast. This brought warm and
pleasant conditions to the Midwest, Great Lakes, and Northeastern US, while the
Southern and Central Plains remained uncomfortably hot. The North saw sunny
skies with highs in the 70s and 80s, but the South reached into the 90s. Air
quality remained poor over the urban areas of eastern Texas because high
pressure acts to trap pollutants near the surface. Favorable fire weather
conditions moved from the Northern Rockies to the Northern Plains. These areas
were placed under Fire Weather Advisories due to highs reaching into the 90s,
dry surface conditions, and winds gusts up to 30 mph. Further West, a trough of
low pressure pushed some moisture over the West Coast. This brought a few patchy
clouds to the Pacific Northwest, as well as low clouds and fog to the coastal
areas of California.
Jim G. Munley, jr.
http://www.jimmunleywx.com
